Skip to main content
MORPHOLOGY AND EVOLUTION
digits are as in the other Apes and Man; that is to say, the thumb is short, the middle finger is the longest, and the index and ring fingers are longer than the fifth finger. The digital formula expressing these relative lengths is 3 > 2 •= 4 > 5 > 1. The thumb and its metacarpal bone can be passively abducted till the latter is almost at right angles to the metacarpal bone of the index finger.
FIG. 13 -The Silvery Gibbon (Hylobates l&uciscus).
The thumb is provided with a flat nail, but the other digits have naiŁ highly arched transversely, or long claws projecting considerably beyond the fingers. In the Bornean Gribfcon the second, third and fourth digits have arched nails, stnd the fifth digit alone can be said
to possess a claw. N
In the white-hande^ Gibbon the claw-like appearance